A couple more thoughts-
I didn't catch the straight-cut gears part; some are noisier than others, and while initially the sound is really cool, a lot of guys find it gets old fast. If you want the wife to spend a lot of time with you, the extra noise may not go over so well (hey- another reason for splurging for aluminum pushrods!). As I mentioned before, I've run an engine like this on the street (1750, W125, ported 40x35 heads, 44IDF's and 1 1/2" exhaust) and it was a lot of fun, but it didn't really get on the powerband to 3,000 or 3500rpm. It was great for surprising the sh*t out of a lot of Camaro and Mustang owners (most didn't take well to being beaten by a VW). With close 3rd and 4th gears (needed with the narrower powerband and small displacement)it was surprisingly fast considering it's size, but if you're main interest is more cruising around the engine should be in it's most efficient phase a little lower in the powerband.
Don't get me wrong, this much power (140hp or thereabouts if everything is right) in a Speedster would be so much fun! That's more power than the original Carrera equipped cars. This is why I (and others) are always advocating stroker engines; the increase in displacement (and lower rod ratio with a longer stroke crankshaft) creates an engine with the same amount of power (or more), but at a lower rpm and with way more power "under the curve", or in the lower rpms where we do most of our driving. This negates the need for close gears (and resulting slower highway speeds) to make the best use of the powerband in the higher strung, smaller engine. The bigger, milder cammed engine will also get upwards of 30mpg on the highway and decent mileage around town when driven sanely; I know, so hard to do, but isn't it great to know it's possible?
I always thought the perfect street engine was that 1750, only bigger. It's really too bad I never got around to stroking it...
Hope this helps, Ted. I know it's not what you want to hear... Al